Alarm system to help Shenzhou 7 avoid debris

Source: CCTV.com | 09-26-2008 10:09

Shenzhou 7 fitted with alarm system to avoid space debris

Without any wind or clouds, spacecraft can appear to be travelling peacefully once in the vacuum of space. But unexpected bits of space debris pose significant risks to the spacecraft and their astronauts. Shenzhou 7 is fitted with an alarm system that leaves nothing to chance.

Around our only planet float numerous pieces of space debris.

They come from Earth, but now are going nowhere. Left by rockets and satellites, or even from the remains of spaceship explosions, the amount of debris is building, and poses an increasing threat to spacecraft missions.

Du Heng, Consultant China Space Debris Group, said, "The International Space Station has to take action to avoid space debris about four times a year for safety reasons. Of course it's not definite that the station would collide with the objects if no measures were taken. But if a crash were to happen, the station would be ruined."

Scientists estimate over tens of millions of objects are in space circling the earth, and those from 1 to 10 centimeters are the most dangerous ones. They're the most difficult to track due to their small size and uncertain path.

Du Heng said, "The threat from these pieces is decided by their energy, which can be determined by their speed. For example, the power from a peanut in space is equal to that from car going 100 kilometers an hour speed on earth."

Space debris also poses a threat to Shenzhou 7. But an alarm system has been installed to deal with the possible danger.

The system can discover all objects within 200 kilometers of the spacecraft, and can track their orbit. The system's computer can also figure out the objects' position and distance to the ship, and calculate the rate of collision.

Du Heng said, "If we predict the path of the objects and the spacecraft, we can alter the orbit of the craft using its motor. Measures to raise or lower the orbit, or change its flying coordinates, will enable it to avoid a collision."

The alarm system designed by Chinese scientists is expected keep a close eye on all the neighboring space debris. And various plans are in place to ensure the safety of the ship from take-off to landing.

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Editor:Du Xiaodan